This part of ISO 19901 specifies methodologies for a) the design, analysis and evaluation of stationkeeping systems for floating structures used by the oil and gas industries to support 1) production, 2) storage, 3) drilling, well intervention and production,4) production and storage, 5) drilling, well intervention, production and storage, and b) the assessment of stationkeeping systems for site-specific applications of mobile offshore units (e.g. mobile offshore drilling units, construction units, and pipelay units). Most stationkeeping systems used with the class of floating structures covered by a) are termed “permanent mooring systems”, for which this part of ISO 19901 is applicable to all aspects of the life cycle and includes requirements relating to the manufacture of mooring components, as well as considerations for in-service inspections. Most stationkeeping systems used with mobile offshore units, the class covered by b), are termed “mobile mooring systems”. Throughout this part of ISO 19901, the term “floating structure”, sometimes shortened to “structure”, is used as a generic term to indicate any member of the two classes, a) and b). This part of ISO 19901 is applicable to the following types of stationkeeping systems, which are either covered directly in this part of ISO 19901 or through reference to other guidelines: - spread moorings (catenary, taut-line and semi-taut-line moorings);- single point moorings, anchored by spread mooring arrangements; - dynamic positioning systems; - thruster-assisted moorings. Descriptions of the characteristics and of typical components of these systems are given in Annex A